The ring portion of steering wheels of automobiles or motor boats has been improved for enhancing the sense of touch of drivers through elasticity afforded and coverage with leather. However, yet there is no such a steering wheel which has been improved for giving good thermal feeling to driver through temperature adjustment of the grip portion of said ring portion. Therefore the conventional steering wheel has a disadvantage that the steering wheel is cooled to a considerably low temperature by the low external air temperature in case the parking is continued for a long period in the winter season, and a driver receives thermal shock from the cooled ring portion at the initial stage of driving.
Some steering wheels comprising a heating generating material such as a heating wire in the ring portion have therefore been proposed. In such steering wheels, there is a problem that the heat of heating generating material is not transmitted effectively solely to the surface of ring portion, but is transmitted also to the center of ring portion and spoke and thereby a longer period is taken until the surface of ring portion is heated up to the predetermined temperature and application efficiency of heat is correspondingly lowered.